Smoke Damage >> How To DIY How To Repair A House Damaged By Smoke

Effects on Smoke on Functional Circuits SNL also tested complete and functional circuit boards for their susceptibility to damage from smoke [18]. These boards contained five functional circuits that could be energized and How To DIY How To Repair A House Damaged By Smoke monitored during smoke exposure. Each circuit was present twice on each board, built with either surface-mount technology (SMT) or pin through hole (PTH) components. 

Half of the boards tested were How To DIY How To Repair A House Damaged By Smoke protected with a polyurethane conformal coating. The circuits included thefollowing: High-Voltage Low-Current (HVLC): This high-resistance series of capacitor-resistorpairs was subject to a 300 Vdc bias. The nominal current was 6 μA. Within the networkitself, the potential difference between any two adjacent copper traces was 60 Vdc. 

High-Current Low-Voltage (HCLV): This circuit contained a number of How To DIY How To Repair A House Damaged By Smoke resistors andcapacitors in parallel. A constant-current power supply adjusted the applied voltage tomaintain 1 A through the nominal 1.43 Ω. High-Speed Digital (HSD): This circuit simply connected a series of NAND logic gates.

While powered, a 5 V, 20 ns input pulse was applied to the first gate, and the output ofthe final gate was monitored. Increases in the rise, How To DIY How To Repair A House Damaged By Smoke fall and delay (relative to input) timesof the output square pulse all indicate degradation of a circuit. High-Frequency Low-Pass Filter (HFLPF): a system of inductors and capacitorsconfigured to attenuate high frequency input signals. 

Before and after exposure, thefilters were tested for signal attenuation from 50 MHz to 1 GHz. During exposure, theywere tested for: attenuation at 50 MHz, 250 MHz and How To DIY How To Repair A House Damaged By Smoke the frequencies at whichattenuation reached -3 and -40 dB. High-Frequency Transmission Line (HFTL): this circuit was two adjacent PCB coppertraces, designed to exhibit 50 Ω impedance. 

It is expected that a small amount of a signalon one line will be transmitted to the other. This behavior, How To DIY How To Repair A House Damaged By Smoke referred to as coupling, isfrequency dependent and is expected to increase with the conductivity between the lines.During exposure, coupling between the lines was measured at 50 MHz, 500 MHz and 1GHz. 

Pre- and post-exposure tests added measurements of coupling with the second lineconnected in a reversed configuration.In addition to the functional circuits, additional components on the board were tested for leakagecurrents before, during and How To DIY How To Repair A House Damaged By Smoke after exposure. Further leakage current measurements wereperformed using an interdigitated comb test board. 

Each board had four distinct comb patternsand during exposure, two were biased with 5 Vdc and the other two with 30 Vdc.The tests used the standard exposure method, How To DIY How To Repair A House Damaged By Smoke with fuel loads of 3 g/m3, 25 g/m3and 50 g/m3heated with 50 kW/m2 and 25 kW/m2. Soot deposition was measured with two quartz crystalmicrobalances (QCM), one oriented vertically and the other oriented horizontally. 

The quantitiesdeposited and fuel burned are listed below in Table 2. Note that the 25 kW/m2heat fluxexposures caused smoldering of the fuel while the 50 kW/m2flux caused flaming. No direct measurements of corrosion were performed, How To DIY How To Repair A House Damaged By Smoke but visual inspection of componentsshowed that components made of reactive metals (such as nickel) had corroded significantlyafter the test.

The HVLC circuit showed susceptibility to smoke exposure. Resistance decreased noticeablywith smoke density and recovered somewhat after venting of the chamber. Conformal coatings were very effective at preventing or limiting resistance losses for all fuel loads. In this particular circuit, How To DIY How To Repair A House Damaged By Smoke the PCB traces were the most vulnerable to damage because they carried the highestpotential differences and were more closely spaced than the leads of attached components.

Because this vulnerability was independent of the types of components attached, there was noobserved difference between PTH and SMT.The HCLV circuit was largely insensitive to smoke. Because the circuit had a very low initial resistance, How To DIY How To Repair A House Damaged By Smoke the addition of weakly conductive alternate paths would have little impact. 

Theexception was the case of the bare (having no conformal coating) SMT board. In all of the medium and high fuel load tests, How To DIY How To Repair A House Damaged By Smoke the resistance of these circuits increased measurably (0.9 % -1.7 %) and did not recover after venting. This change is attributed to corrosion of contacts or solder joints. None of the changes in these tests represented a significant effect on systemperformance.

The HSD circuit was tested for its response to a 20 ns, +5 Vdc pulse by measuring the output risetime, fall time and delay. Changes in signal degradation due to differences in cable length makedirect comparison between pre-test results and in situ measurements invalid. However, How To DIY How To Repair A House Damaged By Smoke none ofthe circuits showed significant change in response to changing fuel loads or the presence ofconformal coatings. 

Previous work indicates that the highest fuel load used would have causedfailure due to circuit bridging in complementary metal-oxide semiconductor (CMOS) chips, How To DIY How To Repair A House Damaged By Smoke but that advanced Schottky transistor to transistor logic (FAST TTL), such as those in the HSD, areless sensitive.The HFLPF did not show any response to smoke. 

However, How To DIY How To Repair A House Damaged By Smoke active measurement duringexposure was performed with an input frequency (250 MHz) that would not be impacted bychanges in system capacitance due to debris (the expected failure mode). Post-test measurements over a wider range of frequencies showed no change from the pre-test condition.

It was expected that the most severe changes in capacitance would occur during exposure, How To DIY How To Repair A House Damaged By Smoke when the testing method would be unable to measure those changes.The HFTL circuit was tested to determine coupling between two adjacent lines. Coated boardsshowed no change in coupling during or after exposure. 

The bare board experienced a large (from -52 dB to -17 dB) increase in coupling of 50 MHz signals during exposure. Coupling on the bare board returned to pre-test values quickly after venting of the test chamber. At high frequencies (500 MHz and 1 GHz) coupling on the bare board actually decreased during smoke exposure and How To DIY How To Repair A House Damaged By Smoke returned to pre-test values after venting. 

Leakage current data are presented only for the PTH boards and the interdigitated comb; leakage data for other components in the methodology section were not reported. Resistance on the bareboards dropped as fuel load increased and How To DIY How To Repair A House Damaged By Smoke recovered somewhat after venting. 

Changes in the interdigitated comb were less consistent, but surface resistance generally decreased with increasing fuel loads and How To DIY How To Repair A House Damaged By Smoke partially recovered after venting. Results in Table 4 are presented inthe change of Log10(R) between pre-test values and average during smoke exposure.

Flood Water Backing Up

Steps to Responding to a Water Emergency The Water Department is dedicated to providing San Diego with a safe and reliable water supply. While the Water Operations Division and Capital Improvements Program help to maintain and improve our water system, Water Damage Flood Water Backing Up unexpected water emergencies sti  read more..

Debris Disposal From Hurricane Winds

Modify disaster assistance employee deployment processes to ensure that Incident Management Assistance Teams and other FEMA first responders include one or more debris specialists with the experience and management skills to assist communities in the crucial early stages of planning and Debris Removal Debris Disposal From Hurricane Winds impleme  read more..

Tools For Restoring Flood Damaged Electronics

Other manufacturer-supplied test data shed light on the typical behavior of tantalum polymer capacitors after exposure to various environmental stresses. Sanyo provided data that describe the typical response of their capacitors to dry heat, moisture, solder reflow conditions, and Electronic Restoration Tools For Restoring Flood Damaged Electronics DC   read more..

Protecting Against Wind Damage

Protecting Against Wind Damage Protecting Your Home or Small Business From Disasters 3-8 Protecting Windows Installing storm shutters is one of the best ways to protect your home or Wind Damage Protecting Against Wind Damage place of business from hurricane damage. Purchase or make storm shutters for all exposed windows, glass  read more..

Physical Symptoms Of A Meth Lab In Your Apartment

CLEANUP PROCEDURES FOR SOIL, GROUNDWATER AND SURFACEWATER
If areas of soil, surface water or groundwater contamination Meth Lab Cleanup Physical Symptoms Of A Meth Lab In Your Apartment are present, characterizationand cleanup of these areas should be conducted by a professional environmentalcontractor, in consultation with the CT Department  read more..

Wind Damage To Trees

Wind damage to trees AL FERRER SEMINOLE COUNTY URBAN HORTICULTURIST The impact of hurricanes on trees varies from simple defoliation to broken branches, split branch crotches and trunks, leaning or falling trees. While no tree can be guaranteed to stand up to hurricane-force winds, there are some tr  read more..

Basic Facts About Bats And Bat Exclusion

Little Brown Bat Did You Know? Bats are the only mammals that can fly. They are insect-eating machines, eating thousands of mosquitoes and other flying insects in a single night. Bats use echolocation (rapid pulses of sound that bounce off an object) to detect and Animal Damage Basic Facts About Bats And Bat Exclusion catch insects.   read more..

House Mold

Remediate moisture and house mold problems Fix moisture problem, implement repair plan and/or maintenance plan Dry wet, non- Mold Remediation House Mold materials within 48 hours to prevent house mold growth Clean and dry house mold materials Discard house moldy porous items that can't be cleaned Questions to Consider  read more..

Tropical Hurricane Hugo Storm Damage

Hurricane Hugo in 1989 was the most powerful Wind Damage Tropical Hurricane Hugo Storm Damage and rainstorm to hit the United States since 1969 when Camille hit the Gulf Coast. Hugo was disastrous and caused extensive residential wind damage, widespread lifeline annihilation, and massive timber devastation in South Carolina. The rainst  read more..

How To Restore Flood Damaged Archive Photos

To create a collection, to inherit one, or to be given oversight of a collection, is also to create, inherit or accept a great responsibility. The challenge for collecting institutions is to meet the charge of stewardship and to assure that their valued collections, whether works of art, historical   read more..